Biocompatible biomedical occlusion device

ABSTRACT

A device for a tissue channel includes a device frame, a shape memory polymer foam segment coupled to the device frame, and an attachment structure coupled to the device frame. The device frame includes a proximal structure, a distal structure, and an intermediate structure coupled to the proximal structure and the distal structure. The proximal structure is configured to collapse to fit into a delivery structure and expand to block migration of the proximal structure. The distal structure is configured to collapse to fit into the delivery structure and expand to block migration of the distal structure. The intermediate structure is configured to fit in the tissue channel upon device deployment. The shape memory polymer foam segment is configured to compress to fit into the delivery structure and occlude the channel. The attachment structure is configured to attach and detach the device from a delivery guide.

PRIORITY CLAIM

This application is a continuation of U.S. patent application Ser. No.15/567,682, filed Oct. 19, 2017, which is a § 371 national stage ofinternational application PCT/US2016/028789, which filed Apr. 22, 2016,which claims priority to U.S. Provisional Patent Application No.62/151,863 filed on Apr. 23, 2015 and entitled “BIOCOMPATIBLE BIOMEDICALOCCLUSION DEVICE.” The content of each of the above applications ishereby incorporated by reference.

TECHNICAL FIELD

The present disclosure relates to occlusion devices. In particular, itrelates to occlusion devices for tissue channels.

BACKGROUND

In humans and animals, defects may form in tissues due to creation of achannel through a tissue wall or failure of a channel in a tissue wallto close. For example, the ductus arteriosus is a vessel connecting thepulmonary artery to the aorta in human and animal neonates, shuntingblood flow around the developing lungs. The ductus arteriosus typicallycloses shortly after birth. However, in some individuals, the ductusarteriosus may stay open, leading to a defect known as patent ductusarteriosus (PDA). PDA may lead to clinical conditions such as cardiacarrhythmias, congestive heart failure, and pulmonary over-circulation.Other conditions or defects involving open tissue channels includepatent foramen ovale, ventricular septal defects, and atrial septaldefects. Previous attempts to seal these tissue defects have involvedsurgical ligation, an invasive procedure that may lead to complications.

BRIEF DESCRIPTION OF THE DRAWINGS

Features and advantages of embodiments of the present invention willbecome apparent from the appended claims, the following detaileddescription of one or more example embodiments, and the correspondingfigures. Where considered appropriate, reference labels have beenrepeated among the figures to indicate corresponding or analogouselements.

FIG. 1A is an exemplary diagram of a device having two sets of strutsand a cylindrical proximal structure, and a discoid distal structureaccording to an embodiment.

FIG. 1B is an exemplary diagram of a device having two sets of strutsand a plug-shaped proximal structure, according to an embodiment.

FIG. 2A is an exemplary diagram of a device having a single set ofstruts and a distally-tapered conical teardrop proximal structure,according to an embodiment.

FIG. 2B is an exemplary diagram of a device having a single set ofstruts and a conical proximal structure, according to an embodiment.

FIG. 3 is an exemplary diagram of a device having two sets of strutsjoined by a backbone structure, according to an embodiment.

FIG. 4 is an exemplary diagram of a device having elastic wires and endsupport structures, according to an embodiment.

FIG. 5A is an exemplary diagram of a device having elastic wires in aflower configuration and a backbone structure, according to anembodiment.

FIG. 5B is an exemplary diagram of a device having elastic wires in aflower configuration and a backbone structure, according to anembodiment.

FIG. 6 is an exemplary diagram of a device having elastic wires in cageconfigurations and a backbone structure, according to an embodiment.

FIG. 7 is an exemplary flow chart for manufacturing an elastic metaldevice, according to an embodiment.

FIG. 8 is an exemplary flow chart for manufacturing a shape memorypolymer device, according to an embodiment.

FIG. 9 is an exemplary flow chart for manufacturing a non-monolithicdevice having elastic wires and end structures, according to anembodiment.

FIG. 10 is an exemplary flow chart for manufacturing a non-monolithicdevice having elastic wires and a backbone structure, according to anembodiment.

FIG. 11 is an exemplary process according to an embodiment.

FIG. 12 is an exemplary process according to an embodiment.

FIG. 13A and FIG. 13B respectively depict an embodiment with expandedstruts and an unactuated foam and an embodiment with expanded struts andan actuated foam.

DETAILED DESCRIPTION

Reference will now be made to the drawings wherein like structures maybe provided with like suffix reference designations. In order to showthe structures of various embodiments more clearly, the drawingsincluded herein are diagrammatic representations ofsemiconductor/circuit structures. Thus, the actual appearance of thestructures, for example in a photo, may appear different while stillincorporating the claimed structures of the illustrated embodiments.Moreover, the drawings may only show the structures useful to understandthe illustrated embodiments. Additional structures known in the art maynot have been included to maintain the clarity of the drawings. “Anembodiment”, “various embodiments” and the like indicate embodiment(s)so described may include particular features, structures, orcharacteristics, but not every embodiment necessarily includes theparticular features, structures, or characteristics. Some embodimentsmay have some, all, or none of the features described for otherembodiments. “First”, “second”, “third” and the like describe a commonobject and indicate different instances of like objects are beingreferred to. Such adjectives do not imply objects so described must bein a given sequence, either temporally, spatially, in ranking, or in anyother manner. “Connected” may indicate elements are in direct physicalor electrical contact with each other and “coupled” may indicateelements co-operate or interact with each other, but they may or may notbe in direct physical or electrical contact.

The disclosure includes a device and methods for making a device for atissue channel having a proximal opening and a distal opening thatincludes a device frame, a shape memory polymer foam segment coupled tothe device frame, and an attachment structure coupled to the deviceframe. The device frame has a central axis and includes a proximalstructure, a distal structure, and an intermediate structure coupled tothe proximal structure and the distal structure. The proximal structureis configured to collapse to fit into a delivery structure and expand toblock migration of the proximal structure through the proximal opening.The distal structure is configured to collapse to fit into the deliverystructure and expand to block migration of the distal structure throughthe distal opening. The intermediate structure is configured to fit inthe tissue channel upon device deployment. The shape memory polymer foamsegment coupled to the device and configured to compress to fit into thedelivery structure and expand to occlude flow through the channel. Theattachment structure is configured to attach and detach the device froma delivery guide.

According to embodiments of the disclosure, a device may be configuredfor minimally-invasive delivery into a tissue channel and secureocclusion of flow through the channel. This device may include anexpandable frame configured to compress into a delivery structure andexpand to secure the device into the tissue channel upon deployment. Thedevice may have an expandable shape memory polymer foam segment coupledto the device and configured to expand and occlude flow through thechannel. The device may have an attachment structure for attaching anddetaching the device from a deployment mechanism.

For deployment, the device may be compressed into a delivery structure,such as a catheter. The delivery structure may be placed past the distalopening of the tissue channel and the device slowly pushed out of thedelivery structure. As the device is removed from the deliverystructure, a distal structure of the device frame may actuate and expanddistal to the distal opening of the tissue channel. The device may befurther extracted from the delivery structure, and a proximal structureof the device frame may actuate and expand proximal to the proximalopening of the tissue channel. The shape memory polymer foam segment mayexpand to an area equal to or greater than the area of the channelopening, obstructing flow through the channel. The device may beretracted and replaced until secured into the channel. After the devicehas been placed and secured within the tissue channel, the device may bedetached from the attachment structure of the device and the deliverystructure retracted from the body.

Device Frame

The device frame may be configured to compress into a deliverystructure, expand into a predetermined shape, secure the device into atissue channel, and prevent the device from becoming dislodged. Thedevice frame may collapse to a compressed state to fit into a deliverystructure. Upon deployment and/or actuation, proximal and distalstructures of the device frame may be configured to expand and securethe device into the channel.

The device frame may include a proximal structure, a distal structure,and an intermediate structure. The proximal structure may correspond tothe section of the device frame configured for placement at or proximalto the proximal opening of the tissue channel. The distal structure maycorrespond to the section of the device frame configured for placementat or distal to the distal opening of the tissue channel. Theintermediate structure may correspond to the section of the device frameconfigured for placement within the channel. These structures may befabricated from a single structure (monolithic) or multiple structures(non-monolithic). The device frame may also include external structures,such as radiopaque markers.

The device frame may contain radial support structures, such as elasticwires and struts, expanding radially from the device axis (spokeconfiguration). These radial support structures may be shaped andconfigured to compress and expand to a preconfigured shape. In additionto radial support, these radial support structures may run laterallydown the proximal, distal, and intermediate structures to form cages.The radial support structures may be integrated as monolithic structuresor coupled to radial coupling structures, such as backbone structuresand end structures (hub configuration). The device frame may provideaxial support for connecting the proximal and distal structures throughan intermediate structure, such as continuous struts, a strut-freemonolithic structure, or a backbone structure (axis configuration).

Monolithic Design

In embodiments of the disclosure, the device frame may be a monolithicdesign fabricated from a single, continuous material. For example, theproximal structure, distal structure, and intermediate structure may beformed from a single, continuous tube, where the struts are cut andpositioned from the tube. In some embodiments, the proximal and distalstructures each may have 2-30 struts.

Multiple Sets of Struts

In embodiments of the disclosure, the monolithic device frame may have aproximal structure made from at least a first set of struts and a distalstructure made from a second set of struts. An intermediate structuremay couple the proximal and distal structure. FIG. 1A and FIG. 1B areexemplary diagrams of monolithic device frames having two sets ofstruts, according to embodiments of the disclosure.

FIG. 1A is an exemplary diagram of a device 100 having two sets ofstruts and a cylindrical proximal structure, according to embodiments ofthe disclosure. The device 100 includes a monolithic device frame 110, ashape memory polymer foam segment 120, an attachment structure 130, anda backbone structure 140. The monolithic device frame 110 furtherincludes a proximal structure 111, a distal structure 112, and anintermediate structure 113. The proximal structure 111 and the distalstructure 112 are formed from two separate sets of struts 114 andcoupled by the intermediate structure 113. The proximal structure 111has a cylindrical shape, the distal structure 112 has a disc shape, andthe shape memory polymer foam segment 120 has a cylindrical shape. Theshape memory polymer foam segment 120 is coupled to the backbonestructure 140 and contained within the proximal structure 111. Thebackbone structure 140 is coupled to the monolithic device frame 110 andposition approximately along the central axis of the device 100. Theattachment structure 130 is a segment on the monolithic device frame 110that contains threads for attaching a threaded guide wire.

As a note, the backbone structure 140 does not need to go through theentire device in all embodiments. For example, backbone structure 140may be present in only section 111, sections 111 and 113, or sections111, 113, and 112.

FIG. 1B is an exemplary diagram of a device 150 having two sets ofstruts and a plug-shaped proximal structure, according to embodiments ofthe disclosure. The device 150 includes a monolithic device frame 160, ashape memory polymer foam segment 170, an attachment structure 180, anda backbone structure 190. The monolithic device frame 160 furtherincludes a proximal structure 161, a distal structure 162, and anintermediate structure 163. The proximal structure 161 and the distalstructure 162 are formed from two separate sets of struts 164 andcoupled by the intermediate structure 163. The proximal structure 161has a tapered plug shape, the distal structure 162 has a disc shape, andthe shape memory polymer foam segment 170 has a tapered plug shape. Theshape memory polymer foam segment 170 is coupled to the backbonestructure 190 and contained within the proximal structure 171. Thebackbone structure 190 is coupled to the monolithic device frame 160 andpositioned approximately along the central axis of the device 150. Theattachment structure 180 is a segment on the monolithic device frame 160that contains threads for attaching a threaded guide wire.

One Set of Struts

In addition to a multiple strut set design, the device frame may beconstructed from a single set of continuous struts running the length ofthe device frame. FIG. 2A and FIG. 2B are exemplary diagrams of deviceshaving a single set of continuous struts, according to embodiments ofthe disclosure.

FIG. 2A is an exemplary diagram of a device 200 having a single set ofstruts and a distally-tapered conical teardrop proximal structure,according to embodiments of the disclosure. The device 200 includes amonolithic device frame 210, a shape memory polymer foam segment 220,and an attachment structure 230. The monolithic device frame 210 furtherincludes a proximal structure 211, a distal structure 212, and anintermediate structure 213. The proximal structure 211, distal structure212, and intermediate structure 213 are formed from the same set ofstruts 214. The proximal structure 211 has a distally-tapered (i.e.,narrows as it moves distally) conical teardrop shape, the distalstructure 212 has a concave disc shape, and the shape memory polymerfoam segment 220 has a modified hourglass shape. The shape memorypolymer foam segment 220 is coupled to the monolithic device frame 210and contained within the proximal structure 211, distal structure 212,and intermediate structure 213. The attachment structure 230 is asegment on the monolithic device frame 210 that contains threads forattaching a threaded guide wire.

While FIG. 2A shows a concave face on distal portion 212 otherembodiments may include a concave face on proximal portion 211 and someembodiments may include concave faces on portions 211 and 212.

FIG. 2B is an exemplary diagram of a device 250 having a single set ofstruts and a conical proximal structure, according to embodiments of thedisclosure. The device 250 includes a monolithic device frame 260, ashape memory polymer foam segment 270, and an attachment structure 280.The monolithic device frame 260 further includes a proximal structure261, a distal structure 262, and an intermediate structure 263. Theproximal structure 261, distal structure 262, and intermediate structure263 are formed from the same set of struts 264. The proximal structure261 has a conical teardrop shape, the distal structure 262 has a concavedisc shape, and the shape memory polymer foam segment 270 has a modifiedconical teardrop shape. The shape memory polymer foam segment 270 iscoupled to the monolithic device frame 260 and contained within theproximal structure 261 and intermediate structure 263. The attachmentstructure 280 is a segment on the monolithic device frame 260 thatcontains threads for attaching a threaded guide wire.

While the concave face of portion 262 is on the proximal face of portion262, in other embodiments a concave face may be on the distal face ofportion 262. More generally, embodiments may include a concave face on adistal portion (on the distal and/or proximal faces of the distalportion) while other embodiments may include a concave face on aproximal portion (on the distal and/or proximal faces of the proximalportion) 211 and some embodiments may include concave faces on distaland proximal portions (on the distal and/or proximal faces of the distaland/or proximal portions).

Non-Monolithic Design

In embodiments of the disclosure, the device frame may be made frommultiple, separate pieces (non-monolithic). For example, the proximalstructure may formed from a first tube and the distal structure a secondtube, with the proximal and distal structures joined together by anintermediate tube or wire.

Two Struts and Backbone Structure

In embodiments of the disclosure, the non-monolithic device frame may beformed from two sets of struts, each forming the proximal structure andthe distal structure, coupled to a backbone, forming the intermediatestructure. FIG. 3 is an exemplary diagram of a device 300 having twosets of struts joined by a backbone structure, according to embodimentsof the disclosure. The device 300 includes a non-monolithic device frame310, a shape memory polymer foam segment 320, an attachment structure330, and a backbone structure 340. The non-monolithic device frame 310further includes a proximal structure 311, a distal structure 312, andan intermediate structure 313. The proximal structure 311 and the distalstructure 312 are formed from two separate sets of struts 314 coupled byan intermediate structure 313. The proximal structure 311 has acylindrical shape, the distal structure 312 has a disc shape, and theshape memory polymer foam segment 320 has a cylindrical shape. The shapememory polymer foam segment 320 is coupled to the non-monolithic deviceframe 310 and contained within the proximal structure 311. The backbonestructure 340 forms the intermediate structure 313 and couples theproximal structure 311 and the distal structure 312. The attachmentstructure 330 is a segment on the non-monolithic device frame 310 thatcontains threads for attaching a threaded guide wire.

Elastic Wires and End Structures

In embodiments of the disclosure, the non-monolithic device frame may beformed from a set of elastic wires attached to end support structures.These elastic wires may be preconfigured to a particular shape, whereinsections of each elastic wire may correspond to the proximal, distal,and intermediate structures once arranged and coupled to an end supportstructure. For example, a profile of the preconfigured shape of anelastic wire may have a first maxima corresponding to the proximalstructure, a minima corresponding to the intermediate structure, and asecond maxima corresponding to the distal structure. In someembodiments, the device may have 2-40 elastic wires for the deviceframe.

FIG. 4 is an exemplary diagram of a device 400 having elastic wires andend support structures, according to embodiments of the disclosure. Thedevice 400 includes a non-monolithic device frame 410, a proximal shapememory polymer foam segment 421, a distal shape memory polymer foamsegment 422, and an attachment structure 430. The non-monolithic deviceframe 410 further includes a proximal structure 411, a distal structure412, and an intermediate structure 413. The proximal structure 411further includes a proximal end structure 441 and the distal structure412 further includes a distal end structure 442. The proximal structure411 and distal structure 412 are formed from the same set of elasticwires 414. The elastic wires 414 are attached proximally to the proximalend structure 441 and distally to the distal end structure 442. Theproximal structure 411 has a proximally concave cylindrical shape, thedistal structure 412 has a proximally flat disc shape, the proximalshape memory polymer foam segment 421 has a cylindrical shape, and thedistal shape memory polymer foam segment 422 has a proximally flat discshape. The proximal shape memory polymer foam segment 421 is containedwithin and coupled to the proximal structure 411, and the distal shapememory polymer foam segment 422 is contained within and coupled to thedistal structure 412. The attachment structure 430 is a segment on theproximal end structure 441 that contains threads for attaching athreaded guide wire.

Elastic Wire Braces and Backbone

In embodiments of the disclosure, the device frame may be formed fromone or more sets of elastic wires coupled to a central backbone. Theseelastic wires may be arranged in a flower configuration to form petalsthat are configured to expand upon removal of an external restraint,such as the delivery tube. In some embodiments, the device may have 2-40petals for each of the distal and proximal structures.

FIG. 5A is an exemplary diagram of a device 500 having elastic wires ina flower configuration and a backbone structure, according toembodiments of the disclosure. The device 500 includes a non-monolithicdevice frame 510, a shape memory polymer foam segment 520, an attachmentstructure 530, and a backbone portion 540. The non-monolithic deviceframe 510 further includes a proximal structure 511, a distal structure512, and an intermediate structure 513. The proximal structure 511 andthe distal structure 512 are formed from two separate sets of elasticwires 514 which form flower configurations and coupled by theintermediate structure 513. The proximal structure 511 has a disc shape,the distal structure 512 has a disc shape, and the shape memory polymerfoam segment 520 has a concave cylindrical shape. The shape memorypolymer foam segment 520 is coupled to the backbone structure 540proximal to the flower cage of the proximal structure 511. The backboneportion 540 forms the intermediate structure 513 of the non-monolithicdevice frame 510. The attachment structure 530 is a segment on thenon-monolithic device 500 that contains threads for attaching a threadedguide wire.

FIG. 5B is an exemplary diagram of a device 550 having elastic wires ina flower configuration and a backbone structure, according toembodiments of the disclosure. The device 550 includes a non-monolithicdevice frame 560, a shape memory polymer foam segment 570, an attachmentstructure 580, and a backbone portion 590. The non-monolithic deviceframe 560 further includes a proximal structure 561, a distal structure562, and an intermediate structure 563. The proximal structure 561 andthe distal structure 562 are formed from two separate sets of elasticwires 564 which form flower configurations and coupled to theintermediate structure 563. The proximal structure 561 has a disc shape,the distal structure 562 has a disc shape, and the shape memory polymerfoam segment 570 is in a compressed, non-actuated shape. The shapememory polymer foam segment 570 is coupled to the backbone portion 590and contained within the intermediate structure 563. The backboneportion 590 forms the intermediate structure 563 of the non-monolithicdevice frame 560. The attachment structure 580 is a segment on thenon-monolithic device 550 that contains threads for attaching a threadedguide wire.

Elastic Wire Cage and Backbone

FIG. 6 is an exemplary diagram of a device 600 having elastic wires cageconfigurations and a backbone structure, according to embodiments of thedisclosure. The device 600 includes a non-monolithic device frame 610, ashape memory polymer foam segment 620, an attachment structure 630, anda backbone structure 640. The non-monolithic device frame 610 furtherincludes a proximal structure 611, a distal structure 612, and anintermediate structure 613. The proximal structure 611 and the distalstructure 612 are formed from two separate sets of elastic wires 614which form cage configurations and are coupled by the intermediatestructure. The proximal structure 611 has a disc shape, the distalstructure 612 has a disc shape, and the shape memory polymer foamsegment 620 is in a compressed, non-actuated shape. The shape memorypolymer foam segment 620 is coupled to the backbone portion 640 andcontained within the proximal structure 611. The backbone portion 640forms the intermediate structure 613 of the non-monolithic device frame610. The attachment structure 630 is a separate segment attached to thenon-monolithic device frame 610 that contains threads for attaching athreaded guide wire.

Proximal, Distal, and Intermediate Structures

The proximal structure may be configured to expand to a diameter greaterthan the proximal opening of the tissue channel to block the proximalstructure from migrating through the proximal opening. The shape of theproximal structure may be configured based on selection criteriaincluding, but not limited to, proximal opening shape, proximal cavityshape, flow characteristics, and foam shape. For example, the proximalopening of the tissue channel may be tapered out; in this case, adistally tapered plug-shaped proximal structure having an angle of 5-85degrees from the central axis may be desired, to better fit to theproximal opening. As another example, the proximal structure may beconfigured to anticipate flex once deployed by including a concavedistal surface to accommodate the flex and maintain a flat surface onthe tissue wall around the proximal opening. The shape of the proximalstructure may include, but is not limited to, discs, cylinders, concavecylinders, plugs, teardrops, cones, and tapered blocks.

The size of the proximal structure may be configured based on selectioncriteria including, but not limited to, proximal cavity size, proximalopening size, ratio of proximal structure diameter to proximal openingdiameter, and shape memory polymer foam segment size. For example, inembodiments where the shape memory polymer foam is contained in theproximal structure, the proximal structure may be shaped to accommodatethe foam segment while limiting movement. In some embodiments, theproximal structure may have a diameter of 2-60 mm and a length of 0.5-10mm.

The distal structure may be configured to expand to a diameter greaterthan the distal opening of the channel to place the device duringdeployment and block the device from moving through the distal opening.For example, during device deployment, the distal structure may firstexit the delivery device and expand into a distal cavity at the distalopening of the channel. The shape of the distal structure may beconfigured based on selection criteria including, but not limited to,distal opening shape, proximal cavity shape, flow characteristics, andshape memory polymer foam shape. The shape of the distal structure mayinclude, but is not limited to, discs, concave discs, flat discs, cones,and tapered blocks.

The size of the distal structure may be configured based on selectioncriteria including, but not limited to, distal cavity size, distalopening size, ratio of distal structure diameter to distal openingdiameter, and foam size. In some embodiments, the distal structure mayhave a diameter of 2-60 mm. and a length of 0.5-2 mm. For someapplications having a proximal cavity at the proximal opening and/or adistal cavity at the distal opening, the proximal structure and/ordistal structure may be configured to expand to contact one or moresurfaces of the proximal cavity or distal cavity.

The intermediate structure may be positioned between the proximalstructure and the distal structure and configured to fit in the channelafter deployment. The size and shape of the intermediate structure mayvary based on factors including, but not limited to, the diameter of thetissue channel, the length of the tissue channel, the shape memorypolymer foam segment dimensions, and the design of the device frame. Forexample, for a device frame having continuous struts or elastic wiresthrough the frame, the intermediate structure may be designed to have adiameter greater than the tissue channel diameter, but less than theproximal and distal structure diameters and capable of being fitted intothe tissue channel. In some embodiments, the intermediate structure mayhave a length of 0.1-20 mm and a diameter 0.1-20 mm less than the lesserof the greatest proximal structure diameter and distal structurediameter.

The device frame may be constructed of elastic, biocompatible materialshaving a high strain recovery. In some embodiments, a shape memory alloyhaving a strain recovery of 3% may be used (however other embodimentsare not so limited and may include shape memory elements with strainrecovery of 4%, 6%, 8%, 10% or more). Materials that may be usedinclude, but are not limited to: shape memory alloys; titanium alloys,such as nitinol; copper-base alloys, such as Cu—Al—Ni; platinum alloys,such as Fe—Pt; chromium-cobalt alloys, such as Co—Cr—Mo; cadmium-basealloys, such as Ag—Cd; shape memory polymers, such as urethane; andstainless steel. The device frame may be comprised of combinations ofmaterials; for example, the proximal segment may be nitinol, theintermediate segment may be stainless steel, and the distal segment maybe Co—Cr—Mo.

Backbone Structure

According to embodiments of the disclosure, a backbone structure mayprovide structure to the device frame and support the shape memorypolymer foam segment. In some device designs, such as non-monolithicdesigns with non-continuous proximal and distal structures, the backbonestructure may form the intermediate structure and connect the proximaland distal structures along the axis of the device. In other designs,the backbone structure may be part of the distal structure, proximalstructure, or intermediate structure. The backbone structure may alsosecure or support the shape memory polymer foam segment. The shapememory polymer foam segment may be coupled to the backbone structure,such as through adhesion, compression, or foam formation on the backbonestructure.

The backbone structure may be positioned along the central axis of thedevice for part or all of the device length. The backbone structure maybe secured to the device at one or more points. For example, if theshape memory polymer foam segment is located in the proximal structure,the backbone may be located in the proximal structure and attached atthe proximal end (e.g., element 441 of FIG. 4) to support contraction ofthe proximal structure length during deployment. For example and usingFIG. 4 for illustrative purposes, in an embodiment a backbone (notpresent in FIG. 4 but is present in other versions of the embodiment ofFIG. 4) is connected to the proximal cage stem 441 and the distal cagestem 442. Regardless of whether the struts are a SM alloy or other SMmaterial (e.g., SMP), the backbone may be a SM material such as a SMP.The SMP backbone may be linear and have a non-actuated first length anda linear actuated second length (which is shorter than the firstlength). Thus, the SMP backbone would shorten or contract upon actuationwhile still providing support to expanding struts. With relativelylarger devices this may help control torsion and other forces that mayhinder deployment of the struts (i.e., may help the struts not tanglewith each other). Factors that may influence where to position thebackbone include, but are not limited to, shape memory polymer foamsegment location, frame type, and frame expansion and contractionproperties.

The backbone structure may be comprised of any biocompatible materialcapable of supporting the shape memory polymer foam segment orconnecting of the proximal and distal structures. Materials that may beused include, but are not limited to: shape memory alloys; titaniumalloys, such as nitinol; copper-base alloys, such as Cu—Al—Ni; platinumalloys, such as Fe—Pt; chromium-cobalt alloys, such as Co—Cr—Mo;cadmium-base alloys, such as Ag—Cd; shape memory polymers, such asurethane; and stainless steel. The backbone structure may be solid, suchas a wire or rod, or may be open, such as a tube or mesh. Factors thatmay influence backbone structure material selection include, but are notlimited to, tensile strength for structure connection, surface roughnessfor shape memory polymer adhesion, biocompatibility, andbiodegradability.

Shape Memory Polymer Foam Segment

According to embodiments of the disclosure, the device may contain ashape memory polymer foam segment. The shape memory polymer foam segmentmay be used to compress into a delivery tube, actuate and expand upondeployment, and occlude flow through the channel. For certainapplications, the shape memory polymer may also promote healing, tissuemigration, or clotting. The shape memory polymer foam segment may becoupled to the device, including the device frame and a backbonestructure. The shape memory polymer foam segment may be positioned atvarious locations on or in the device frame including, but not limitedto, the proximal structure, the distal structure, the intermediatestructure, or combinations of the aforementioned structures.

According to embodiments of the disclosure, the shape memory polymerfoam segment may be comprised of any shape memory foam capable ofcompressing into a delivery tube as a temporary shape, actuating from anexternal stimulus after delivery, and expanding to block a channel as apermanent shape. Shape memory polymers that may be used include, but arenot limited to: thermally-induced shape memory polymers, such asthermoset or thermoplastic shape memory polymers that includepolyurethanes, polyethylene terephthalate (PET), and polyethylene oxide(PEO); photon-induced shape memory polymers, such as shape memorypolymers with cinnamamide moieties; laser-actuated shape memorypolymers; chemically-actuated shape memory polymers; andelectrically-actuated shape memory polymers, such as carbonnanotube-filled shape memory polymers.

Shape memory polymers may be tailored to or selected for properties thatmay include, but are not limited to: transition temperatures, foamdensity, shape recovery, type and mechanism of actuation,biodegradability, volume recovery, cell structure, cellinterconnectedness, porosity, and surface adhesion. Types of actuationmay include, but are not limited to, heat, light, laser, and chemical.For example, in some embodiments, the shape memory polymer foam segmentmay actuate on contact with a bodily fluid, such as blood. As anotherexample, for applications in which tissue migration or scaffolding maybe desired, the shape memory polymer may be biodegradable. As anotherexample, for applications involving partial flow, such as bloodclotting, the shape memory polymer foam may have an open cell structure;for applications involving no fluid flow, the shape memory polymer foammay have a closed cell structure. In certain embodiments, the shapememory polymer foam may be configured to a high volume recovery in arange of 50-100.

In addition to the shape memory polymer foam, additives may be includedin the shape memory polymer foam segment. Some additives may be includedto assist in the occlusion function of the device. For example, if thedevice is to be used to occlude a channel for blood flow, a coagulantmay be included. In another example, if the foam or device frame ischemically actuated, a chemical may be included. Additives may also beadded to provide an additional functionality to the device. For example,if healing or tissue migration is desired, a medication may be includedto assist in either of these functions. Additives that may be usedinclude, but are not limited to, coagulants, medications, structurecomponents, actuation agents, and particulate fillers to improve imagecontrast or mechanical properties.

The shape memory polymer foam segment may have a variety of shapes,sizes, and configurations for its permanent and temporary states.Factors that may influence shape and size selection may include, but arenot limited to, device frame shape, proximal structure shape, distalstructure shape, intermediate structure shape, channel shape, channelopening configuration, delivery tube inner diameter. Shapes that may beused include, but are not limited to, plug, cylinder, concave cylinder,hourglass, cone, and tapered block.

Attachment Structure

According to embodiments of the disclosure, the device may include anattachment structure for attaching and detaching the device from adeployment mechanism. The attachment structure may be integrated intoanother part of the device or may be a separate structure. For example,in a monolithic device having a single tube, the end of the tube mayhave threads for receiving a threaded guide wire. In a device having abackbone, a separate attachment structure may be coupled to the device.Mechanisms used for the attachment structure may include, but are notlimited to, threads, notches-and-release, hooks, and magnets.

Manufacture of Monolithic Proximal and Distal Structures

Methods for manufacturing devices having monolithic proximal and distalstructures may include creating struts for a device frame, shape settingthe struts, coupling the shape memory polymer foam segment to thedevice, and configuring the device with an attachment structure.

FIG. 7 is an exemplary flow chart for manufacturing an elastic metaldevice, according to embodiments of the disclosure. A plurality of slotsis cut into an elastic tube, as in 700. Cutting slots in a tube, wire,or rod may create the form of struts used for later formation of theproximal, distal, and/or intermediate structures. For devices havingcontinuous struts down the device frame, a single set of slots may becut; for devices have separate struts for the proximal and distalstructures, two or more sets of struts may be cut subsequently orconcurrently. The struts may be cut by a laser or other precisioncutting device.

The device frame may be shape set, as in 710. Shape setting may involvecreating a permanent shape for the device frame. For metal frames, shapesetting may include molding the device frame to an expanded shape towhich the device returns when radial restrictions are removed, such asthrough deployment from a tube. The device frame shape set of 710 mayinclude forming a device frame, as in 711, and heat treating the deviceframe, as in 712.

Device formation 711 may be performed by setting the tube in a moldstructure and compressing the tube so that the struts expand into apreconfigured shape. Spacers corresponding to desired structure lengthmay be placed in the corresponding section of tube; for example, a 10 mmspacer may be placed in a section of tube corresponding to the proximalstructure, where the desired proximal structure length is 10 mm. Anexternal frame tailored to the desired structure diameter may be placedaround the corresponding section of tube. The tube may be compressedaxially until the lateral struts contact the external frame and/or theinternal radial struts contact the spacer. The process may be appliedsubsequently or concurrently to other sections of the device frame.After formation of the preconfigured shape, the device may be heattreated to create a permanent shape to which the device frame willreturn to once external restrictions are removed. A backbone structuremay be coupled to the device along the device axis, such as throughwelding, adhesion, or tension.

A shape memory polymer foam segment may be coupled to the device, as in720. The shape memory polymer foam segment may be coupled to the deviceframe by mechanisms that include, but are not limited to: adhering theshape memory polymer foam segment to the device frame throughapplication of an adhesive to a portion of the device frame; crimpingthe device frame to the shape memory polymer foam segment; or pressingthe shape memory polymer foam segment into the frame through foampressure. The shape memory polymer foam segment may be coupled to abackbone structure by mechanisms that include, but are not limited to:adhering the shape memory polymer foam segment to the backbone structurethrough application of an adhesive to a portion of the backbonestructure; compressing the shape memory polymer foam segment to thebackbone structure; or forming the shape memory polymer foam segmentdirectly onto the backbone structure.

The device may be configured with an attachment structure, as in 730.Configuring the device with an attachment structure may includemodifying the device to include an attachment and detachment mechanism.For example, if the device tube is formed from a tube, the inside of thetube at the proximal end of the device may be threaded so that a guidewire may be screwed into and unscrewed from the device. Configuring thedevice with an attachment structure may also include coupling a separatestructure having an attachment and detachment mechanism to the device.For example, the screw action discussed above may be attached to theproximal end of the device to accommodate a different size of guidewire.

FIG. 8 is an exemplary flow chart for manufacturing a shape memorypolymer device, according to embodiments of the disclosure. A pluralityof slots may be cut into a shape memory polymer tube, as in 800. Thedevice frame may be shape set, as in 810. The device frame shape set of810 may include forming a device frame, as in 811, and curing the deviceframe, as in 812. Forming the device frame may include molding struts toa preconfigured shape. Alternatively, a shape memory polymer frame maybe created from injection molding.

Curing the device frame may include crosslinking the polymer to create arigid frame in the preconfigured shape. A shape memory polymer foamsegment may be coupled to the device, as in 820, including those methodsdiscussed in 720 of FIG. 7. The device may be configured with anattachment structure, as in 830, including those methods discussed in730 of FIG. 7.

In some embodiments, separate tubes may be used to create monolithicproximal and distal structures, as in FIG. 3. The proximal and distalstructures may be coupled with an intermediate structure, such as abackbone structure. Methods that may be used include, but are notlimited to, welding, adhesion, or tension.

Manufacture of Non-Monolithic Proximal and Distal Structures

Manufacture of devices having non-monolithic proximal and distalstructures may include providing elastic wires for a device frame,coupling the elastic wires to an axial support structure, coupling theshape memory polymer foam segment to the device, and configuring thedevice with an attachment structure.

FIG. 9 is an exemplary flow chart for manufacturing a non-monolithicdevice having elastic wires and end structures, according to embodimentsof the disclosure. Elastic wires are shape set, as in 900. The elasticwire shape set of 900 may include forming the elastic wires, as in 901,and heat treating the elastic wires, as in 902. Alternatively, in shapememory polymer frame designs, elastic wire shape setting may includeinjection molding the elastic wires and curing the wires. The elasticwires are coupled to end structures, as in 910. This may be performed bywelding, soldering, adhesion, screwing, or tension. Holes may be drilledin the end structures to accommodate the elastic wires. A shape memorypolymer foam segment may be coupled to the device, as in 920, includingthose methods discussed in 720. The device is configured with anattachment structure, as in 930, including those methods discussed in730.

FIG. 10 is an exemplary flow chart for manufacturing a non-monolithicdevice having elastic wires and a backbone structure, according toembodiments of the disclosure. Holes may be created in a backbonestructure, as in 1000. Elastic wires may be coupled to the holes createdin 1000, as in 1010. A shape memory polymer foam segment may be coupledto the device, as in 1020, including those methods discussed in 720. Thedevice may be configured with an attachment structure, as in 1030,including those methods discussed in 730.

The following examples pertain to further embodiments.

Example 1

A device for a tissue channel having a proximal opening and a distalopening, comprising: a device frame having a central axis andcomprising: a proximal structure configured to: collapse to fit into adelivery structure; expand to block migration of the proximal structurethrough the proximal opening; a distal structure configured to: collapseto fit into the delivery structure; expand to block migration of thedistal structure through the distal opening; an intermediate structurecoupled to the proximal structure and the distal structure andconfigured to fit in the tissue channel upon device deployment; a shapememory polymer foam segment coupled to the device frame and configuredto: compress to fit into the delivery structure; expand to occlude flowthrough the channel; and an attachment structure coupled to the deviceframe and configured to attach and detach the device from a deliveryguide.

Example 2

The device of example 1, further comprising a backbone structure coupledto the device frame and located approximately along the central axis ofthe device frame.

Example 3

The device of example 2, wherein the backbone structure is an elastic,biocompatible material.

Example 4

The device of example 3, wherein the backbone structure is comprised ofa titanium alloy, a platinum alloy, a chromium-cobalt alloy, a shapememory polymer, or stainless steel.

Example 5

The device of example 1, wherein: the shape memory polymer foam segmentis further configured to expand radially to a cross sectional areagreater than an area of the proximal opening; the proximal structure isfurther configured to expand radially to a diameter greater than adiameter of the proximal opening; and the distal structure is furtherconfigured to expand radially to a diameter greater than a diameter ofthe distal opening.

Example 6

The device of example 1, wherein the shape memory polymer foam segmenthas a volume recovery in a range of 50-100.

Example 7

The device of example 1, wherein at least a portion of the shape memorypolymer foam segment is open cell.

Example 8

The device of example 1, wherein the shape memory polymer foam segmentcontains a filler.

Example 9

The device of example 8, wherein the filler comprises a hydrogel, ablood additive, a coagulant, a medication, or a particulate filler toimprove image contrast or mechanical properties.

Example 10

The device of example 1, wherein the shape memory polymer foam segmentis actuated with laser irradiation, a solvent, or body heat.

Example 11

The device of example 1, wherein the shape memory polymer foam segmentis configured to expand to a cylindrical, conical, hourglass, or diamondform.

Example 12

The device of example 1, wherein the shape memory polymer foam segmentis 1-30 mm in diameter.

In another version of Example 12 the device of example 1, wherein theshape memory polymer foam segment is 1-60 mm in diameter.

Example 13

The device of example 1, wherein the shape memory polymer foam segmentis comprised of a proximal segment in the proximal structure and adistal segment in the distal structure.

Example 14

The device of example 1, wherein the shape memory polymer foam segmentis secured within the device frame through adhesion to the device frame,crimping the device frame to the foam, or outward foam pressure on thedevice frame.

Example 15

The device of example 2, wherein the shape memory polymer foam segmentis secured to the backbone portion by adhesion to the backbone structureor foam compression on to the backbone portion, or foam formationdirectly over the backbone portion.

Example 16

The device of example 5, wherein: the proximal structure is configuredto: expand to a diameter greater than a diameter of the proximal openingby a factor of 2-5; compress to a diameter less than an inner diameterof the delivery structure; the distal structure is configured to: expandto a diameter greater than a diameter of the distal opening by a factorof 1.5-5; and compress to a diameter less than the inner diameter of thedelivery structure.

Example 17

The device of example 1, wherein the proximal structure and the distalstructure are each comprised of an elastic frame of struts.

Example 18

The device of example 1, wherein the device frame is comprised of anelastic biocompatible metal configured to recover from deformations.

Example 19

The device of example 18, wherein the elastic biocompatible metal is ashape memory alloy.

Example 20

The device of example 18, wherein the device frame is comprised of atitanium alloy, a platinum alloy, a chromium-cobalt alloy, acopper-aluminum alloy, or stainless steel.

Example 21

The device of example 1, wherein: the proximal structure has a diameterof 2-40 mm and a length of 0.5-10 mm; and the distal structure has adiameter of 2-40 mm and a length of 0.5-2 mm.

Example 22

The device of example 1, wherein the device frame is a monolithic shapememory polymer frame comprised of a shape memory polymer.

Example 23

The device of example 22, wherein at least a portion of the shape memorypolymer frame contains a laser-absorbing dye.

Example 24

The device of example 23, wherein the shape memory polymer frame isconfigured for actuation by laser irradiation, a solvent, or body heat.

Example 25

The device of example 22, wherein the shape memory polymer frame isbiodegradable.

Example 26

The device of example 22, wherein the shape memory polymer frame isconfigured to undergo plasticization from contact with a solvent fromthe delivery structure.

Example 27

The device of example 1, wherein the proximal structure is in the formof a cylinder, concave cylinder, tapered cylinder, cone, plug, or disc.

Example 28

The device of example 1, wherein the distal structure is in the form ofa cone, flat disc, or concave disc.

Example 29

The device of example 1, wherein a proximal end of the proximalstructure is 1-5 mm greater than a distal end of the proximal structure.

Example 30

The device of example 1, wherein the proximal structure is in a conicalform with a tapered surface at a proximal end of the proximal structureand wherein the tapered surface forms a 5-85 degree angle relative tothe central axis of the device frame.

Example 31

The device of example 1, wherein the proximal structure is in a form ofa cylinder with a concave surface at a proximal end of the proximalstructure and wherein the concave surface forms a 5-85 degree anglerelative to the central axis of the device frame.

Example 32

The device of example 1, wherein the distal structure is in a form of aconcave disc with a concave surface at a distal end of the distalstructure and wherein the concave surface has a 5-85 degree anglerelative to the central axis of the device frame.

Example 33

The device of example 14, wherein the proximal structure and the distalstructure are each comprised of 2-30 struts.

Example 34

The device of example 33, wherein the struts are straight or helixed.

Example 35

The device of example 33, wherein the proximal structure, intermediatestructure, and distal structure are comprised of continuous struts.

Example 36

The device of example 33, wherein the proximal structure is comprised ofa first set of struts and the distal structure is comprised of a secondset of struts.

Example 37

The device of example 2, wherein the proximal structure and the distalstructure are comprised of one or more sets of elastic wires in flowerconfigurations and are connected to the backbone structure.

Example 38

The device of example 33, wherein: each flower configuration iscomprised of 2-60 petals; and the proximal structure and the distalstructure are each 4-40 mm in diameter.

Example 39

The device of example 37, wherein the proximal structure and the distalstructure each have two or more interwoven sets of elastic wires.

Example 40

The device of example 37, wherein the sets of elastic wires are attachedapproximately perpendicular to the axis of the device frame.

Example 41

The device of example 37, wherein the flowers are curved proximally ordistally.

Example 42

The device of example 1, wherein the device contains a radiopaque markeron at least one of the proximal structure, distal structure, orintermediate structure.

Example 43

The device of example 2, wherein the proximal, distal, and intermediatestructures are comprised of a plurality of elastic wires coupled to thebackbone structure at a proximal end and a distal end of the device.

Example 44

The device of example 43, wherein the proximal, distal, intermediatestructures are comprised of 2-50 elastic wires.

Example 45

The device of example 1 wherein the proximal and distal structures areformed from two different elastic materials.

Example 46

The device of example 1, wherein the intermediate structure has adiameter less than 1-10 mm of the lesser of a diameter of the proximalstructure or a diameter of the distal structure.

Example 47

The device of example 1, wherein the intermediate structure has a lengthof 0.1-20 mm.

Example 48

The device of example 18, wherein the intermediate structure isconfigured to shorten axially when actuated.

Example 49

The device of example 1, wherein the device is monolithic and theintermediate structure forms a depression in a profile of the deviceframe.

Example 50

The device of example 1, wherein the attachment structure is threaded.

Example 51

The device of example 1, wherein: the tissue channel couples a proximalvascular cavity and a distal vascular cavity; and the proximal structureis configured to contact at least a surface of the proximal vascularcavity.

Example 52

The device of example 51, wherein the tissue channel is a patent ductusarteriosus.

Example 53

The device of example 51, wherein the tissue channel is a patent foramenovale.

Example 54

The device of example 51, wherein the tissue channel is a ventricularseptal defect.

Example 55

A method for creating a device for a tissue channel, comprising:creating a plurality of slots in one or more elastic tubes; shapesetting the one or more elastic tubes to a preconfigured shape to form adevice frame having a proximal structure, a distal structure, and anintermediate structure, wherein the proximal structure and distalstructure each have a larger diameter than the intermediate structure;configuring an attachment structure to the device frame; and coupling ashape memory polymer foam segment to the device frame.

Example 56

The method of example 55, wherein: the plurality of slots are continuousthrough the proximal structure, distal structure, and intermediatestructure; and the device frame is comprised of a single elastic tube.

Example 57

The method of example 55, wherein: the device frame is comprised of asingle elastic tube; creating a plurality of slots further comprises:creating a first plurality of slots in a first section of the singleelastic tube; creating a second plurality of slots in a second sectionof the single elastic tube; shape setting the elastic tube to apreconfigured shape further comprises: shape setting the first sectionof the single elastic tube to form the proximal structure; shape settingthe second section of the single elastic tube to form the distalstructure.

Example 58

The method of example 55, wherein: creating a plurality of slots furthercomprises: creating a first plurality of slots in a first section of afirst elastic tube; creating a second plurality of slots in a secondsection of a second elastic tube; shape setting the elastic tube to apreconfigured shape further comprises: shape setting the first sectionof the first elastic tube to form the proximal structure; shape settingthe second section of the second elastic tube to form the distalstructure; and coupling the proximal structure and the distal structurewith the intermediate structure.

Example 59

The method of example 55, further comprising coupling a supportstructure to a distal end of the device frame.

Example 60

The method of example 55, further comprising coupling a backbonestructure to the device frame.

Example 61

The method of example 55, wherein coupling the shape memory polymer foamsegment further comprises adhering the shape memory polymer foam segmentto the device frame with an adhesive.

Example 62

The method of example 55, wherein coupling the shape memory polymer foamsegment further comprises crimping the device frame to the shape memorypolymer foam segment.

Example 63

The method of example 60, wherein coupling the shape memory polymer foamsegment further comprises adhering the shape memory polymer foam segmentto the backbone structure.

Example 64

The method of example 60, wherein coupling the shape memory polymer foamsegment further comprises compressing the foam to the backbonestructure.

Example 65

The method of example 60, wherein coupling the shape memory polymer foamsegment further comprises depositing the shape memory polymer foamsegment on the backbone during foam formation.

Example 66

The method of example 55, wherein: the elastic tube is comprised of athermoplastic shape memory polymer; shape setting the one or moreelastic tubes further comprises curing the thermoplastic shape memorypolymer.

Example 67

A method for creating a device for a tissue channel, comprising:creating an elastic device frame through one of injection molding,additive manufacturing, or subtractive manufacturing, wherein the deviceframe has a proximal structure, a distal structure, and an intermediatestructure, and wherein the proximal structure and distal structure eachhave a larger diameter than the intermediate structure; configuring anattachment structure to the device frame; and coupling a shape memorypolymer foam segment to the device.

Example 68

The method of example 68 wherein: the elastic device frame is comprisedof a thermoplastic shape memory polymer; and creating the elastic devicefurther comprises curing the thermoplastic shape memory polymer.

Example 69

The method of example 68, wherein curing the thermoplastic shape memorypolymer further comprises cross-linking the thermoplastic shape memorypolymer.

Example 70

A method for creating a device for a tissue channel, comprising:coupling a plurality of elastic wires to one or more axis supportstructures to form a device frame with a preconfigured shape having aproximal structure, a distal structure, and an intermediate structure,wherein the proximal structure and the distal structure each have adiameter greater than a diameter of the intermediate structure;configuring an attachment structure to the device frame; and coupling ashape memory polymer foam segment to the device.

Example 71

The method of example 70: wherein the one or more axis supportstructures further comprise: a proximal end structure; a distal endstructure; wherein each elastic wire in the plurality of elastic wireshas a proximal end and a distal end; further comprising: shape settingeach elastic wire in the plurality of elastic wires to a preconfiguredshape; wherein coupling the plurality of elastic wires furthercomprises: coupling the proximal end of each elastic wire in theplurality of elastic wires to the proximal end structure; and couplingthe distal end of each elastic wire in the plurality of elastic wires tothe distal end structure.

Example 72

A method for creating a device having a proximal section and a distalsection, comprising: creating a first plurality of holes into a firstsection of a backbone structure which corresponds to the proximalsection of the device; creating a second plurality of holes into asecond section of the backbone structure which corresponds to the distalsection of the device; and affixing elastic wires through the firstplurality of holes to form a proximal flower structure and the secondplurality of holes to form a distal flower structure; affixing theattachment structure to the proximal end of the device; and affixing acompressed shape memory polymer foam to the device.

Example 73

The method of example 72, further comprising shape setting the proximaland distal flower structures.

Example 74

A method for creating a device having a proximal section, anintermediate section, and a distal section, comprising: providing aplurality of elastic wires, wherein each elastic wire has a proximal endand a distal end; shape setting each elastic wire to a preconfiguredshape, wherein the preconfigured shape has a first maxima section, aminima section, and a second maxima section; securing the proximal endsof the elastic wires to a proximal end structure and the distal ends ofthe elastic wires to a distal end structure to form a device framehaving a proximal structure from at least a portion of the first maximasection of each elastic wire, a distal structure from at least a portionof the second maxima section of each elastic wire, and an intermediatestructure from at least a portion of the minima section of each elasticwire; affixing an attachment structure to the device frame; and affixinga compressed shape memory polymer foam segment to the device.

Example 75

A method for creating a device having a proximal section and a distalsection, comprising: creating a first plurality of slots into a firstelastic tube which corresponds to the proximal section of the device;creating a second plurality of slots into a second elastic tube whichcorresponds to the distal section of the device; and shape setting thefirst elastic tube to form a proximal structure and the second elastictube to form a distal structure; connecting the first elastic tube andthe second elastic tube with an intermediate section to form a deviceframe; configuring an attachment structure to the device frame; couplinga compressed shape memory polymer foam to the device.

Example 1a

A system comprising: a conduit comprising: (a)(i) a proximal portionincluding proximal struts, (a)(ii) a distal portion including distalstruts, and (a)(iii) a middle portion coupling the proximal struts tothe distal struts; and a shape memory polymer (SMP) foam that expandsfrom an unactuated configuration to an actuated configuration; wherein(b)(i) the proximal and distal struts include a shape memory (SM)material, (b)(ii) the proximal struts expand from a first proximalconfiguration to a second proximal configuration and the distal strutsexpand from a first distal configuration to a second distalconfiguration, (b)(iii) the second proximal configuration has a largermaximum outer diameter than the first proximal configuration and thesecond distal configuration has a larger maximum outer diameter than thefirst distal configuration, and (b)(iv) the SMP foam is, in theunactuated configuration, included within the proximal struts when theproximal struts are in the second proximal configuration.

The SMP foam may actuate based on, for example, being heated beyond itsTg. The heat may be due to blood temperature, optics, electricalresistive heating, and the like. For example, FIGS. 3 and 4 depictproximal and distal struts in the “second proximal configuration” and“second distal configuration”. The “first proximal configuration” and“first distal configuration” may exist when the device is containedwithin a deployment conduit, such as a sheath or catheter. The struts“expand” in that they, for example, assume a larger outer diameter oncedeployed from a sheath (where the diameter is measured radially andorthogonally to the central axis of the device). The proximal and distalstruts may be monolithic with each other (e.g., FIG. 4) or not (e.g.,FIG. 3). The middle portion may include struts (e.g., FIG. 4) or may notinclude struts (e.g., FIG. 3). Regarding the SMP foam being includedwithin the proximal struts, FIGS. 1A and 2A both show such a situation.

As another example, see FIGS. 13A and 13B. FIG. 13A shows an embodimentwith the struts in the second proximal and second distal configurations(i.e., expanded) but with the foam in an unactuated state. FIG. 13Bshows an embodiment with the struts in the second proximal and seconddistal configurations but with the foam in an actuated state. FIG. 13Amay depict the device at a manufacturing facility before the device isincluded in a sheath and packaged for shipping to customers.

Example 2a

The system of example 1a, wherein the proximal, middle, and distalportions are all part of the conduit and are all monolithic with eachother.

For example, the three portions may be cut from a conduit and orextruded in such a fashion they all form the conduit and are monolithic(i.e., formed from a single unit and not coupled via welding, adhesives,and the like).

Example 3a

The system of example 2a wherein the middle portion includes no struts.

For example, see FIG. 1A. This is not to say the distal and proximalstruts are not, for example, cut from a single conduit. FIG. 1A merelyshows a contiguous ring (that includes no struts) in area 113.

Example 4a

The system of example 1a, wherein the SMP foam is monolithic and the SMPfoam is, in the unactuated configuration, included within the middleportion.

For example, see FIG. 2A (albeit this shows the actuated configuration).

Example 5a

The system of example 4a, wherein the SMP foam is, in the unactuatedconfiguration, included within the distal struts when the distal strutsare in the second distal configuration.

For example, see FIG. 2A (albeit this shows the actuated configuration).For example, see FIG. 13A.

Example 6a

The system of example 4a, wherein the SMP foam, in both the unactuatedand actuated configurations, is included within the proximal struts whenthe proximal struts are in the second proximal configuration, the middleportion, and the distal struts when the distal struts are in the seconddistal configuration.

For example, see FIG. 2A. See also, for example, FIG. 12 (C.3). See alsoFIGS. 13A and 13B. When the device of FIG. 13A is included in a sheathor catheter, the distal struts may be deformed forward whereby theunactuated foam may no longer be included within the distal struts. Evenin such a deformed state within a sheath, the unactuated foam may stillbe within the proximal struts.

Example 7a

The system of example 4a, wherein each of the proximal struts aregenerally collinear, respectively, with each of the distal struts whenthe proximal and distal struts are respectively in the second proximaland second distal configurations.

For example, see FIG. 1A or 2B.

Example 8a

The system of example 4a wherein each of the second proximalconfiguration and second distal configuration has a larger outerdiameter than a maximum diameter of the middle portion.

For example, the embodiments of FIGS. 1A, 1B, 2A, 2B include a narrowedwaist. A “maximum” outer diameter of, for example, FIG. 2A for each ofportions 212, 213, 211 are respectfully diameters 212′, 213′, 211′.

Example 9a

The system of example 8a wherein the second proximal configuration has asmaller maximum outer diameter than the second distal configuration.

For example, see FIG. 12 (A.3).

In another version of Example 9a the second proximal configuration has amaximum outer diameter that is less than or equal to a maximum outerdiameter of the second distal configuration.

Example 10a

The system of example 4a, wherein the SMP foam, in the actuatedconfiguration, extends radially from within at least one of the distaland proximal struts respectively in the second proximal and seconddistal configurations to outside and beyond the at least one of thedistal and proximal struts respectively in the second proximal andsecond distal configurations.

For example, See FIG. 12 (A.2) or FIG. 11 (B.3).

Example 11a. The system of example 4a, wherein the SMP foam, in theactuated configuration, extends radially from within the distal strutsin the second distal configuration to outside and beyond the distalstruts in the second distal configuration.

Example 12a

The system of example 4a comprising a monolithic strut that includes oneof the proximal struts and one of the distal struts and which extendsthrough the middle portion.

For example, see FIG. 4.

Example 13a

The system of example 4a, wherein: the SMP foam has a length thatextends from a proximal end of the SMP foam to a distal end of the SMPfoam; the SMP foam is fixedly attached to the system along only aportion of the length and is not fixedly attached to the system alonganother portion of the length.

For example, the SMP foam may be 320 of FIG. 3 may fixedly couple toportion 330 but may slideably couple to more distal portions of member340. In FIG. 11(C.1) to FIG. 11(C.2) notice how the foam slides alongmember 1140 (although this does not show the foam fixedly attached to,for example, element 1130).

Example 14a

The system of example 13a comprising a central member that is proximalto the middle portion, wherein: the SMP foam includes first and secondportions; the first portion is fixedly attached to the first centralmember; and the second portion is slideably coupled to the centralmember.

A central member may include, for example, element 1130 of FIG. 11 orelement 340 of FIG. 3. In FIG. 11(B.1) the foam is on the proximalportion of backbone 1130 and in FIG. 11 (B.2) the foam is on the distalportion of backbone 1130. Thus, in these two figures the foam isslideably coupled to the backbone and is not fixedly attached to thebackbone. However, in other embodiments a portion of the foam may befixedly attached to the system (e.g., to the backbone or a portionanalogous to portion 441 of FIG. 4) and another portion may be slidablycoupled to the system (e.g., to the backbone).

Example 15a

The system of example 4a, wherein the SM material is selected from thegroup comprising: a SM alloy and a SMP.

Example 16a

The system of example 4a, wherein a proximal face of the proximalportion is generally concave in the second proximal configuration with afocus that is proximal to the proximal face.

See, for example, “focus” 430′ of FIG. 4. The proximal face of portion411 is an example of “generally concave.” In some embodiments, such asFIG. 2A, the distal element may include a concave proximal face.

Example 17a

The system of example 4a, wherein: the proximal portion includes aproximal most end and the distal portion includes a distal most end; theproximal most end is monolithic with the proximal struts and theproximal struts terminate at a distal portion of the proximal most end;and the distal most end is monolithic with the distal struts and thedistal struts terminate at a proximal portion of the distal most end.

For example, see ends 442 and 441 of FIG. 4.

Example 18a

The system of example 1a comprising: an additional conduit comprising:(c)(i) an additional proximal portion including additional proximalstruts, (c)(ii) an additional distal portion including additional distalstruts, and (c)(iii) an additional middle portion coupling theadditional proximal struts to the additional distal struts; and anadditional SMP foam; wherein (d)(i) the additional proximal andadditional distal struts include the SM material, (d)(ii) the additionalproximal struts expand from an additional first proximal configurationto an additional second proximal configuration and the additional distalstruts expand from an additional first distal configuration to anadditional second distal configuration; (d)(iii) the additional secondproximal configuration has a larger maximum outer diameter than theadditional first proximal configuration; and (d)(iii) the additional SMPfoam is included within the additional proximal struts when theadditional proximal struts are in the additional second proximalconfiguration; wherein the conduit includes a maximum outer diameterwhen the proximal and distal struts are in the first proximalconfiguration and the first distal configuration; wherein the additionalconduit includes a maximum outer diameter when the additional proximaland distal struts are in the additional first proximal configuration andthe additional first distal configuration; wherein the maximum outerdiameter of the conduit is equal to the maximum outer diameter of theadditional conduit and the maximum outer diameter of the additionalsecond proximal configuration is larger than the maximum outer diameterof the second proximal configuration.

For example, two tubes or conduits of equal outer diameter (and possiblyequal length in some embodiments but not in others) may be treateddifferently to form devices with different maximum diameters. Forexample a first tube may have shorter slits formed in it than a secondtube. After the SMA struts are set, the longer struts may have a greaterouter diameter (once expanded) than the shorter struts of the firsttube. This provides efficiencies in manufacturing whereby the sameconduits (or at least conduits having the same initial outer diameter)form different devices (devices having larger maximum deployed diameterssuch as diameters 212′ and 211′ of FIG. 2A) based on the formation oflonger slits/struts. In some embodiments, to accommodate significantlylonger struts the tubes may have the same initial outer diameters butdifferent overall lengths).

Example 19a

The system of example 1a comprising an intravascular pusher roddetachably coupled to the conduit.

For example, the pusher rod may be threaded and couple to element 230 ofFIG. 2A. However, other decoupling mechanisms may be used such as, forexample, electrolytic release and the like. A pusher rod may include anycable or member that is stiff enough to be used to push the device outof a delivery conduit (e.g., sheath) and/or withdraw the device from ananatomic anomaly and/or into the delivery conduit.

Example 20a

The system of example 1a comprising an additional SMP foam includedwithin the distal struts when the distal struts are in the second distalconfiguration, wherein the SMP foam is not monolithic with theadditional SMP foam.

For example, see FIG. 4, elements 421, 422.

Example 21a

The system of example 1a, wherein in the second proximal configuration aproximal portion of a first strut included in the proximal struts iscollinear with a wall of the conduit and another portion of the firststrut is not collinear with the wall of the conduit.

For example, in FIG. 13A the most proximal portion of the strut iscollinear with the proximal wall of the conduit but other portions ofthe strut (e.g., midway along the strut forming the proximal cage) thestrut is obviously deployed/expanded with an expanded diameter thatplaces the strut in a non-collinear arrangement with the proximal wallof the conduit. Doing so increases fatigue life for the struts. Tomanufacture such a configuration, the collinear portions addressed abovemay be purposefully constrained during the shaping process (e.g., byplacing a collar over the strut portion and conduit tube one wishes toremain collinear with each other. Using the collars bypasses the stressconcentrations that would occur during bending of struts that are formedat the interface where the strut connects to the tube. The collinearportion of the strut allows for better torsion and angling of the cagesto fit into the expanded strut geometries (e.g., concave and the like)as well.

In an embodiment in the second distal configuration a distal portion ofthe strut is collinear with a wall of the conduit (e.g., distal wall)and another portion of the strut is not collinear with the wall (e.g.,distal wall) of the conduit. See, for example, FIG. 13A.

Example 22a

A system comprising: a conduit with proximal and distal struts thatcomprise a wall of the conduit, the proximal and distal struts eachincluding a shape memory (SM) material; and a shape memory polymer (SMP)foam; wherein (a)(i) the proximal struts are configured to expand toform a proximal cage and the distal struts are configured to expand toform a distal cage; and (a)(ii) the SMP foam is configured to be, in anunactuated state, included in at least one of the proximal and distalcages.

For example, see FIGS. 13A and 13B. The struts may be, for example, SMPor SMA. The SMP foam may be a monolithic piece that extends from theproximal cage to the distal cage or may be, for example, separate foamswith one of the foams in the proximal cage and another in the distalcage.

Example 23a

The system of example 22a, wherein the proximal and distal struts aremonolithic with each other.

Example 24a

The system of example 23a, wherein the proximal and distal cages areseparated from each other by a narrow portion of the conduit that has asmaller maximum diameter than either of the proximal and distal cages.

Example 25a

The system of example 24, wherein the SMP foam is a monolithic foamincluded in the proximal and distal cages.

Thus, embodiments provide numerous advantages.

An embodiment includes a cupped shape (e.g., see portion 411 of FIG. 4).This shape provides a form of stepped locking mechanism that helps lockthe device in place upon deployment and also guides the device back intothe catheter when recapturing the device. For example, the concaveportions provide points of rotation whereby portion 441 is withdrawninto a lumen first. Portion 441 pulls on portion 411 forming a conicalsection with the tip of the cone being withdrawn into the lumen first.The concave aspect of portion 411 facilitates the formation of the cone.

Further, conically shaped distal portions may foster a lower profile forthe device, thereby allowing for smaller inner diameter lumens fordevice deployment. More specifically, in an embodiment the distalportion is flat upon full deployment (e.g., see generally flat proximalface of distal portion 412 of FIG. 12) but the distal portion 412 may beconical in shape during deployment. Thus, portion 412 has anintermediate conical shape that is formed during deployment and ispresent because the still compressed waist struts constrain the distalstruts such that they cannot fully expand.

Radiopaque marker bands may be added at, for example, proximal anddistal ends of the device. If the design allows (monolithic with twodistinct cages separated by a portion of uncut tubing (waist), such asFIG. 1A) a marker band could be placed over the waist/between the twocages.

A threaded mechanism (e.g., area 130) may be located within the proximalstem of an embodiment and attach to a delivery cable (i.e., pusher rod).

Further, a delivery system profile (i.e., compressed device diameter) isdetermined by the outer diameter of the tube from which the struts areformed (or from the compressed diameter of the SMP foam). The advantagesof this are discussed with regard to Example 18a. Regarding Example 18a,please note embodiments provide a “semi-modular” design in that shapesof each portion (proximal, waist, and distal) can be changedindependently of each other based on the application and vesselmorphology it is designed to fit within. By just changing the length ofthe laser cut struts, the diameter of the cages can be increased ordecreased (this is how device size can be changed while preserving thelow delivery system profile), or one can change the fixturing (e.g.,mold used to set the SMA strut expanded configuration) and make acompletely different cage shape for any portion, while keeping theothers the same.

Although the present invention has been described in terms of specificembodiments, it is anticipated that alterations and modificationsthereof will become apparent to those skilled in the art. Therefore, itis intended that the following claims be interpreted as covering allsuch alterations and modifications as fall within the true spirit andscope of the invention.

What is claimed is:
 1. A system comprising: a conduit with proximal anddistal struts that comprise a wall of the conduit, the proximal anddistal struts each including a shape memory (SM) material; and acontiguous single-piece shape memory polymer (SMP) foam including firstand second foam portions; wherein (a)(i) the proximal struts areconfigured to expand to form a proximal cage portion and the distalstruts are configured to expand to form a distal cage portion; and(a)(ii) the SMP foam is configured to be, in an unactuated state,included in at least one of the proximal or distal cage portions; andwherein the first foam portion is configured to slide (b)(i) within theat least one of the proximal or distal cage portions, and (b)(ii)towards the second foam portion.
 2. The system of claim 1, wherein theproximal and distal struts are monolithic with each other.
 3. The systemof claim 2, wherein the proximal and distal cage portions are separatedfrom each other by a narrow portion of the conduit that has a smallermaximum diameter than either of the proximal and distal cage portions.4. The system of claim 1 comprising a central member, wherein: thesecond foam portion is fixedly attached to the central member; the firstfoam portion is slidably coupled to the central member; the centralmember includes a long axis; the first foam portion surrounds thecentral member in a first plane, the first plane being orthogonal to thelong axis; and the second foam portion surrounds the central member in asecond plane, the second plane being orthogonal to the long axis.
 5. Thesystem of claim 1, wherein the first foam portion is configured to slide(b)(i) within the at least one of the proximal or distal cage portions,and (b)(ii) towards the second foam portion while the second foamportion remains fixed within at least one of the at least one of theproximal or distal cage portions or another of the at least one of theproximal or distal cage portions.
 6. The system of claim 1, wherein thefirst foam portion is proximal to the second foam portion.
 7. Anocclusion system for a tissue channel, the system comprising: a framecomprising: (a)(i) a proximal structure portion including proximalstruts, and (a)(ii) a distal structure portion including distal struts;a shape memory polymer (SMP) foam that expands from an unactuatedconfiguration to an actuated configuration; and a central member that isat least partially proximal to the distal structure portion and which isincluded in at least one of the proximal or distal structure portions;wherein (b)(i) the proximal and distal struts include a shape memory(SM) material, (b)(ii) the proximal struts expand from a first proximalconfiguration to a second proximal configuration and the distal strutsexpand from a first distal configuration to a second distalconfiguration, (b)(iii) the second proximal configuration has a largermaximum outer diameter than the first proximal configuration and thesecond distal configuration has a larger maximum outer diameter than thefirst distal configuration, and (b)(iv) the SMP foam is, in theunactuated configuration, included within a proximal opening defined bythe proximal struts when the proximal struts are in the second proximalconfiguration; wherein (c)(i) the SMP foam has a length that extendsfrom a proximal end of the SMP foam to a distal end of the SMP foam; and(c)(ii) the SMP foam is fixedly attached to the central member alongonly a second portion of the length and is slidably coupled to thecentral member along a first portion of the length.
 8. The system ofclaim 7, wherein the SMP foam, in both the unactuated and actuatedconfigurations, is included within each of: (1) the proximal openingdefined by the proximal struts when the proximal struts are in thesecond proximal configuration, and (2) a distal opening defined by thedistal struts when the distal struts are in the second distalconfiguration.
 9. The system of claim 8, wherein the second proximalconfiguration has a smaller maximum outer diameter than the seconddistal configuration.
 10. The system of claim 7, wherein the SMP foam,in the actuated configuration, extends radially from within at least oneof the at least one of the proximal or distal structure portions oranother of the at least one of the proximal or distal structure portionsto outside and beyond the at least one of the at least one of theproximal or distal structure portions or the another of the at least oneof the proximal or distal structure portions.
 11. A system comprising: aconduit comprising: (a)(i) a proximal portion including proximal struts,and (a)(ii) a distal portion including distal struts; and a shape memorypolymer (SMP) foam that expands from an unactuated configuration to anactuated configuration; wherein (b)(i) the proximal and distal strutsinclude a shape memory (SM) material, (b)(ii) the proximal struts expandfrom a first proximal configuration to a second proximal configurationand the distal struts expand from a first distal configuration to asecond distal configuration, (b)(iii) the second proximal configurationhas a larger maximum outer diameter than the first proximalconfiguration and the second distal configuration has a larger maximumouter diameter than the first distal configuration, and (b)(iv) the SMPfoam is, in the unactuated configuration, included within a proximalopening defined by the proximal struts when the proximal struts are inthe second proximal configuration; wherein (c)(i) the SMP foam is notfixedly and directly connected to either of the proximal or distalstruts, and (c)(ii) the SMP foam is configured to expand from theunactuated configuration to the actuated configuration independentlyfrom either of the proximal or distal struts.
 12. The system of claim11, wherein the SMP foam is monolithic.
 13. The system of claim 11,wherein the SMP foam is, in the unactuated configuration, includedwithin a distal opening defined by the distal struts when the distalstruts are in the second distal configuration.
 14. The system of claim11, wherein the SMP foam, in both the unactuated and actuatedconfigurations, is included within the proximal opening defined by theproximal struts when the proximal struts are in the second proximalconfiguration and a distal opening defined by the distal struts when thedistal struts are in the second distal configuration.
 15. The system ofclaim 11, wherein: the proximal struts are configured to expand to forma proximal cage portion and the distal struts are configured to expandto form a distal cage portion; and the SMP foam, in the actuatedconfiguration, extends radially from within at least one of the expandedproximal and distal cage portions to outside and beyond the at least oneof the expanded proximal and distal cage portions.
 16. The system ofclaim 15, wherein the SMP foam, in the actuated configuration, isconfigured to fill a majority of the at least one of the expandedproximal and distal cage portions.
 17. The system of claim 11, wherein:the proximal struts are configured to expand to form a proximal cageportion and the distal struts are configured to expand to form a distalcage portion; and the SMP foam, in the actuated configuration, isconfigured to fill a majority of at least one of the expanded proximaland distal cage portions.
 18. The system of claim 11, wherein the SMPfoam, in the actuated configuration, extends radially from within adistal opening defined by the distal struts in the second distalconfiguration to outside and beyond the distal struts in the seconddistal configuration.
 19. The system of claim 11 comprising a centralmember that is at least partially proximal to the distal portion,wherein: the SMP foam includes first and second foam portions; the firstfoam portion is fixedly attached to the central member; and the secondfoam portion is slidably coupled to the central member.
 20. The systemof claim 11 comprising an additional SMP foam included within a distalopening defined by the distal struts when the distal struts are in thesecond distal configuration, wherein the SMP foam is not monolithic withthe additional SMP foam.